A power steering apparatus includes a power cylinder including first and second pressure chambers, a hydraulic pump including first and second discharge ports, the hydraulic pump being arranged to supply a hydraulic pressure selectively to the first and second pressure chambers; first and second hydraulic passages connecting the first and second pressure chambers and the first and second discharge ports; a motor arranged to drive the hydraulic pump; a motor control section configured to output a drive signal to the motor; a reservoir tank storing a hydraulic fluid; first and second bypass passages connecting the first and second hydraulic passages and the reservoir tank; first and second bypass valves arranged to open and close the first and second bypass passages; and first and second flow rate restricting sections disposed in the first and second bypass passages, and arranged to decrease flow rates of the first and second bypass passages.